Intermediate Filament

• Named for diameter (8-12 nm) • Only found in cells of some animals (Microtubules and microfilaments are found in all animal cells) • Bear tension •Different types of intermediate filaments → All made using a particular protein subunit from the keratin family • More permanent than microtubules and microfilaments • Outer layer of skin has dead skin cells with keratin filaments still in them • Very sturdy • Reinforce shape of cell • Fix position of certain organelles – Nucleus sits in a cage of intermediate filaments – Nuclear lamina made of intermediate filaments (line inside of nuclear envelope)